1. Field of the Invention
The present invention relates to elastic nonwoven fabric and fiber products manufactured therefrom. More specifically, it relates to elastic nonwoven fabric having a good elasticity, adequate strength under elongation, good antiblocking property, and favorable feeling, which is relatively inexpensive and suitable for fiber products.
2. Description of the Related Art
Elastic nonwoven fabrics have often been used recently to improve body fitting of clothes to the body. Such fabrics are particularly suitable for disposable diapers, clothes, caps, bandages and tapes due to their comfortable fit, elasticity and stretching property. While thermoplastic elastomers are often used to obtain nonwoven fabrics with such properties as mentioned above, most thermoplastic elastomers tend to show higher adhesiveness with higher elasticity. This renders elastic nonwoven fabrics made from highly elastic thermoplastic elastomers unsuitable, or at most usable only with uncomfortable feeling, for products directly applied to the skin under clothes.
Another problem of such nonwoven fabrics is the adhesiveness, by which the component fibers stick to each other during production or storage, particularly under high temperatures and the weight of a pile in storage in summer, which results in a higher tension needed for unwinding a roll of such a nonwoven fabric, thus often leading to excessive stretch or breakdown of the product. Low adhesiveness, or antiblocking nonwoven fabric is needed to solve this problem.
A method for obtaining good antiblocking property is to spin the fiber for nonwoven fabrics from a mixture of a thermoplastic elastomer with a low adhesiveness polyolefin, as disclosed in Reference 1. However, the nonwoven fabric obtained in this manner shows an insufficient antiblocking property due to scarcity of the polyolefin on the fiber surface, and a low elasticity due to the polyolefin that has only a low elasticity, and is thus unsuitable for uses mentioned above.
Another invention provides a nonwoven fabric consisting of an elastomeric fiber made from a thermoplastic elastomer blended with a nonelastomeric fiber made from a nonelastomeric thermoplastic, as disclosed in Reference 2. This product is, however, a simple mixture of the two fibers without any attempt to obtain high elasticity and antiblocking property simultaneously. In fact, a composition of elastomeric fiber/nonelastomeric fiber=30/70 on the weight basis described in the examples 1 and 2 of the invention, present in an excessive proportion of the nonelastomeric fibers, without any treatment to endow the fabric a high elasticity, cannot provide the excellent performance desired.
Patent Reference 1
Japanese Patent Application Laid-Open No. 7-81230
Patent Reference 2
Japanese Patent Application Laid-Open No. 2002-242069